Green synthesis of multifunctional silver nanoparticles using quercetin and their therapeutic potential

Active species used in bio-chemical for synthesizing nanoparticles is poly phenolic compounds. The ability of flavonoids (e.g. quercetin) to dissolve in water is low and the production of metallic nanoparticles from them in the aqueous medium is hard. Previous studies recommend that quercetin was not capable of reducing Ag+ to Ag0. The current research aimed at synthesizing quercetin-mediated silver nanoparticles (Q-AgNPs) and evaluate the antioxidant and anticancer activities of Q-AgNPs in vitro.

The green synthesis of Q-AgNPs in an aqueous medium has been demonstrated. The resultant nanoparticles were characterized by several analytical techniques of imaging and spectroscopic. The improved antioxidant activity of Q-AgNPs (DPPH and nitric oxide scavenging and iron chelating assay) was determined by the colorimetric method. Possible biomedical applications such as antioxidant and anticancer activities of Q-AgNPs have been assessed.

The DPPH and nitric oxide radical scavenging activity of Q-AgNPs was found to be (IC50=46.47±1.79 and 30.64±3.18μg/mL, respectively). Q-AgNPs exhibited better iron chelating activity than standard EDTA (IC50=3.12 ±0.44μg/mL). Significant anticancer activity of Q-AgNPs (IC50=57.42μg/mL) was found against HepG2 cell lines after 24-hour exposure. Furthermore, the antifungal activity (MIC = 4, 8 and > 64 μg/mL) was found against Candida krusei, Candida parapsilosis and Aspergillus fumigatus, respectively.

The present method is a competitive option to produce multifunctional nanoscale hybrid materials with higher efficiency and using natural sources for diverse biomedical applications such as antioxidant and anticancer activities.